1. Field of Invention
The present invention relates to a bendable wrench and, more particularly, to a connecting device for connecting a head to a handle of a bendable wrench so that the angle between the head and the handle can be changed in a large range and firmly retained.
2. Related Prior Art
Wrenches are often used to tighten and slacken fasteners such as threaded bolts and nuts. Wrenches include one-way wrenches, socket wrenches, open-ended wrenches and box-ended wrenches. A wrench includes a handle and at least one head provided at an end of the handle. To fit in a limited and crooked working environment, there have been devised bendable wrenches such as disclosed in Taiwanese Patent Publication Nos. 450185 and 569860 and Taiwanese Patents I241940 and I242483. Such a bendable wrench includes a handle, a head and a connecting device for connecting to the head to the handle so that the angle between the head and the handle can be changed and retained. There are however problems with these conventional bendable wrenches. Firstly, they include complicate structures made of many components. It is troublesome to make and assemble these components. Secondly, to change the angle between the head and the handle, a user has to operate the connecting device with one hand and change the angle with the other hand, and this is inconvenient. Thirdly, the angle can be changed between only a few pre-determined values. Fourthly, the angle cannot firmly be retained in operation, and this not only interrupts the operation but also imposes a potential danger to the user.
The present invention is therefore intended to obviate or at least alleviate the problems encountered in prior art.